Exemplary embodiments of the invention relate to a rotary-wing aircraft and, more particularly, to a main rotor blade of a rotary-wing aircraft.
Rotary-wing aircraft blades often include a composite or metallic main rotor spar of a constant chord and constant wall thickness. To attach the rotor spar to a hub assembly, a separate root end cuff is attached to an inboard section of the main rotor spar. The cuff is conventionally manufactured of a titanium forging or a composite root laminate sized to match an outer mold line of the main rotor spar. The root end cuff is attached to the main rotor spar through a multiple fastener configuration, each fastener of which must be torqued to a required standard. At the outboard side of the blade, the blade terminates at a tip cap which is non-structural in nature. As such, additional lift is not available from the spar through the tip cap since this portion of the blade does not generate lift.
Although effective, the separate root end cuff assembly and related hub componentry may result in a weight and life cycle penalty as the multiple of components are duplicated on each rotor blade assembly.